Microwave oven



FIG. 1 is a front, side and top perspective view of a microwave oven showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a side elevational view thereof from the left of FIG. 2;

FIG. 4 is a side elevational view thereof from the right of FIG. 2;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for a microwave oven, as shown. 